Internal combustion engine piston



Patented June 4, 1940 UNITED STATES INTERNAL COMBUSTION ENGINE PISTONCharles W. Dake, Grand'Haven, Mich.'

Application March 9, 1938, Serial No. 194,827

Claims.

My present invention pertains to internal combustion engine pistonswhich have to do principally with internal combustion engines whereinthere is a cylindrical bore in which a trunk type 5 piston is caused tomove longitudinally thereof in response to pressure generated bycombustion of an explosive mixture of gases.

The objects of improvement of my piston are: first, to provide a pistonhaving great strength coupled with lightness; second, to provide apiston for internal combustion. engines having an improved heatconduction; third, to provide a piston wherein the head will have greatresistance against burning through; and, fourth, to provide a piston forinternal combustion engines of improved heat transfer to thev enginescylinder walls.

I attain these named objects by the structure hereinafter described withthe assistance of the accompanying drawing, in which Figure 1 is a planview of my piston as looking at the head end thereof, and

Figure 2 is a longitudinal sectional view of my piston taken on line V-Vof Figure 1 looking inI the direction the arrow thereon indicates.

Referring to the drawing, similar numerals refer to similar portions ofthe piston as follows:

Numeral I refers to the piston as a wh le; 2 the head thereof, 3 theskirt portion; 4 the beginning of the skirt portion or thevjuncture ofthe skirt portion and the head portion 5; 6 the upper land; 'I thepiston ring separating land; 8 pressure sealing ring grooves; 9 wristpin accommodating bosses; I0 an inwardly extending reinforcing flange;II head reinforcing or stiffening rib at the under side of the pistonshead. I2 designates a thickness of metal highly impregnated with copperor other metal having a higher heat conduction factor than the ferriebase metal or other 40 metal from which the piston may be composed.

Expert internal combustion engine engineers have 'long recognized thenecessity of improving the transfer of the intense heat generated withinthe combustion spaces of internal combustion engines by combustion tothe cylinder Walls, but until applicants present inventionlittle or noimprovement has been made in the said heat transfer which not onlycauses pre-combustion of the gaseous fuel within the engine, but alsocauses'rapid deterioration of the internal portions of the engine thatthe intense heat contacts and which attacks the pistons 4head mostseverely with the result that the head soon cracks or ruptures, which iscommonly termed burning through, which is due primarily to .the'pistonanot having a suiiiciently high heat conduction or ability to transferheat of combustion to the cyl- "'inder wall and therethrough to beabsorbed by the cooling fluid within the cooling fluid chambervsurrounding the cylinder wall.

In my present improved piston, .which is preferably produced by themethod disclosed in my application for Letters Patent Serial No. 194,826bearing even date hereof for Method of casting internal combustionengine pistons, the piston is preferably cast from a ferric base metalhaving as its principal constituent iron, either in its iron state or aswhen converted into steel, to which is added during its molten state, anon-ferrie base metal such as copper, and as this cast metal con- 15tains copper or some other metal having a higher specific gravity thanthe ferrie base metal, and because of themethodof casting the portion ofthe pistons head designated by I2 which represents the portion of thepiston consisting of almost all 20 copper, which is herein employed forease of description, or very highly impregnated with copper, whichamount or density of impregnation because of the method of castinggradually diminishes with the distance of the portion of the pistonseparated from the said portion I2. That is, the portion I2 of thepistons head will contain the greatest density or amount of copper withthe portion 5 containing less copper, the portion 4 still less and theskirt 3 still less, with the ange I0 containing little or no copper.Therefore the copper or non-ferrie base metal content of the ferrie basemetal of my piston will gradually diminish from a maximum density at thehead portion I2 to the ange I0 at the opposite end of the skirt fromhead 2, which flange will contain little or no copper.

Having described my present improved piston, the rights thereto I desireto secure are set forth in the claims as follows:

1. An internal combustion engine piston having as its principalconstituent, ferric base metal impregnated with a non-ferrie metalhaving a higher heat conduction than the ferrie base metal thereof withthe greater density of impregnation at the pistons head portion exposedto combustion during the engines operation.

2. An internal combustion engine piston having as its principalcomstituent ferric base metal impregnated with a non-ferrie base metal,the 50 degree of impregnation being greatest at the surface of thepiston exposed to combustion during the engines operation.

3. An internal combustion engine piston having as its principalconstituent a ferric base metal impregnated with a metal or metalshaving a higher heat conduction factor than the ferrie base metalthereof, `the degree of impregnation being greatest within the pistonshead.

4. An internal combustion engine piston having skirt and head portionsof which the heat conduction resistance coecient increases from the headportion to the skirt portion.

5. An internal combustion engine piston having as its principalconstituent a ferrous metal having therein a non-ferrous metal sodistributed throughout the ferrous metal that the heat conduction willhave less resistance to ow in the head portion than in the skirtportion.

CHARLES W. DAKE.

